Fix -Wunused-function error in native_stack_sampler_win.cc

base/profiler/native_stack_sampler_win.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <objbase.h>
 #include <windows.h>
 #include <winternl.h>
 
 #include <cstdlib>
 #include <map>
@@ skipping 59 matching lines @@
   NTSTATUS status =
       nt_query_information_thread(thread_handle, ThreadBasicInformation,
                                   &basic_info, sizeof(THREAD_BASIC_INFORMATION),
                                   nullptr);
   if (status != 0)
     return nullptr;
 
   return basic_info.Teb;
 }
 
+#if defined(_WIN64)
 // If the value at |pointer| points to the original stack, rewrite it to point
 // to the corresponding location in the copied stack.
 void RewritePointerIfInOriginalStack(uintptr_t top, uintptr_t bottom,
                                      void* stack_copy, const void** pointer) {
   const uintptr_t value = reinterpret_cast<uintptr_t>(*pointer);
   if (value >= bottom && value < top) {
     *pointer = reinterpret_cast<const void*>(
         static_cast<unsigned char*>(stack_copy) + (value - bottom));
   }
 }
+#endif
 
 // Rewrites possible pointers to locations within the stack to point to the
 // corresponding locations in the copy, and rewrites the non-volatile registers
 // in |context| likewise. This is necessary to handle stack frames with dynamic
 // stack allocation, where a pointer to the beginning of the dynamic allocation
 // area is stored on the stack and/or in a non-volatile register.
 //
 // Eager rewriting of anything that looks like a pointer to the stack, as done
 // in this function, does not adversely affect the stack unwinding. The only
 // other values on the stack the unwinding depends on are return addresses,
@@ skipping 409 matching lines @@
 
   if (thread_handle) {
     return scoped_ptr<NativeStackSampler>(new NativeStackSamplerWin(
         win::ScopedHandle(thread_handle)));
   }
 #endif
   return scoped_ptr<NativeStackSampler>();
 }
 
 }  // namespace base